Re: [Line6linux-devel] UX2 - sysinfo

[Markus G. <gr...@ic...>]

On Thursday 08 December 2011 20:48:02 Stefan Hajnoczi wrote:
> On Thu, Dec 8, 2011 at 4:44 PM, Petter S. Storvik
> 
> <pet...@gm...> wrote:
> > One more thing is; I cant start up computer if device is plugged in. Some
> > sort of error and it goes to text-mode, and then I have to restart
> > without the device. But all seems right if I plug it in after startup.
> 
> This sounds like a kernel panic which can happen if an unexpected
> error occurs when the driver is running.  There is typically a lot of
> text on the screen and it can contain information that allows
> developers to fix the bug that caused the panic.  If you have a camera
> on your phone or digital camera, would you be able to capture the
> error screen?
> 
> I'm guessing that the kernel panic has nothing to do with recording
> not working, they are probably different issues but there's a chance
> they are related.
Yes, indeed, someone recently moved the buffer allocation from 
line6_pcm_start() to snd_line6_[capture|playback]_hw_params :-) However, when 
a TonePort device is plugged in, the driver launches a PCM capture and 
playback stream to provide a software monitor. This is not related to ALSA and 
therefore bypasses ALSA initialization, thus trying to access a buffer via a 
pointer which is still null, resulting in the kernel panic.

I fixed it in the subversion repository and sent the patch to the kernel 
maintainer.

@Petter: could you please try again with the most recent version from 
branches/ux2?

	Kind regards,
		Markus


-- 
Markus Grabner
Institute for Computer Graphics and Vision
Graz University of Technology, Inffeldgasse 16a/II, 8010 Graz, Austria
WWW: http://www.icg.tugraz.at/Members/grabner